SINGAPORE - Expect wetter weather in the second half of August, said the weatherman on Friday (Aug 14).

Thundery showers are expected on most days over the next two weeks between late morning and early afternoon, and could also occur on a few nights, according to the National Environment Agency's Meteorological Service Singapore (MSS).

In addition, widespread thundery showers with gusty winds could sweep through Singapore on one or two mornings.

The MSS said this is because of the passage of Sumatra squalls, which are lines of thunderstorms that usually develop at night over Sumatra or the Strait of Malacca. They typically move east towards Singapore in the early morning hours.

Temperature on most days in the latter half of August should range between 25 deg C and 33 deg C, with highs of around 34 deg C on a few particularly warm days.

A few warm and humid nights are also forecast, with temperatures hovering at about 28 deg C.

In comparison, the highest daily maximum temperature recorded in the first half of the month was 35.4 deg C on August 9 and was above 33 deg C on most days.

Drier weather was also experienced in the first half of August as the monsoon rain band was situated over northern South-east Asia, resulting in drier weather over equatorial South-east Asia, including Singapore. Many areas, such as Sentosa Island, received well below average rainfall.

There were, however, a few days where thundery showers fell over the island due to the passage of the Sumatra squalls.

National water agency PUB said heavy rain on Friday morning caused brief flash floods at the junction of Craig Road and Tanjong Pagar Road, which subsided after 10 minutes.

On Thursday, PUB said a heavy downpour resulted in accumulated water in Aljunied Road, below the Pan-Island Expressway flyover, at around 7am.